This invention relates to a tricycle, and particularly to a tricycle having means for preventing the tricycle from tipping over during turning maneuvers, or when riding over rough terrain.
In conventional tricycles having two rear wheels and a single front wheel, the front wheel is usually steerable (or turnable) to facilitate turning maneuvers. The rider grips the front handlebars to turn the front wheel, to achieve a turning maneuver.
During a vehicle turning maneuver, the center of gravity of the rider and the tricycle tends to shift in the direction of the turn. As a result, one of the rear wheels tends to lift off the ground. In a worst case scenario, the tricycle can tip over. The rider has the perception that the tricycle is unstable.
My U.S. Pat. No. 5,240,267 discloses a tricycle that overcomes the wheel lift-off problem experienced with conventional tricycles. The tricycle shown in U.S. Pat. No. 5,240,267 comprises separate front and rear frames that have an articulated connection, whereby during a turning maneuver the rider can lean with the front frame in the direction of the turn, but the rear frame wheels remain on the ground.
My co-pending U.S. patent application Ser. No. 519,826, filed on Aug. 25, 1995, and has since issued as U.S. Pat. No. 5,730,453 on Mar. 24, 1998, discloses an improvement on the tricycle shown in U.S. Pat. No. 5,240,267. The improvement relates to a chain-sprocket drive means wherein the drive sprocket is located on the front frame and the driven sprocket is located on the rear frame, whereby the drive chain undergoes a twisting motion as the front frame tilts (or leans) from a neutral upright position. The front frame is articulated to the rear frame on a longitudinal axis that intersects the rotational axis of the drive sprocket, so as to minimize the twisting motion of the drive chain.